nent-magnet ( PM ) motor , enables space savings , eases the installation and maintenance and maximizes comfort onboard . The high efficiency of the PM-motor combined with that of contra-rotating propellers ( CRP ) will bring the fuel economy to a whole new level ,” promises Jukola .
IMPROVED MANOEUVRABILITY
Rolls-Royce has developed Promas , an integrated propulsion and manoeuvring system .
” By adapting the propeller and rudder into one propulsive unit , Promas offers increased propulsive efficiency and improved manoeuvrability ”, says Göran Grunditz , Manager of the Rolls-Royce Hydrodynamic Research Centre ( HRC ).
In general the efficiency gain is between 3 to 8 percent for single screw vessels and 2 to 6 percent for twin screw vessels .
” Virtually any vessel will benefit . The position of the rudder in the slipstream and the skeg design can deliver further improvements ,” Grunditz points out .
The Rolls-Royce Promas system comes in a number of forms .
For newbuilds , there is the full Promas . One version of it includes a high efficiency propeller in a nozzle , with a hubcap and specially designed rudder .
Promas Lite is specifically designed for retrofitting to vessels with conventional shaftlines . The main difference in comparison to full Promas is that the existing rudder is normally retained , saving costs with only a small sacrifice in propulsive efficiency . n photo : STEERPROP LTD .
Steerprop Ltd . has launched a new generation of ducted azimuth propulsors with new features and upgraded design specifications . seatec 1 / 2017 43